Structural composites are well known and are used in a wide variety of applications that require plastic parts having a minimum threshold of mechanical properties such as strength and impact resistance while imparting cost savings in terms of manufacturing techniques and in terms of weight reduction. Examples of structural composites include sheet molding compound (SMC), fiber reinforced thermoplastics and structural reinforced injection molding (SRIM).
Introducing glass fiber or other reinforcing material into a thermoplastic or thermosetting polymer material typically makes structural composites. The glass fiber and polymer material may be mixed together and formed into a composite part in a wide variety of methods, including compression molding and injection molding. Structural composites made of glass fiber or other reinforcing material offer generally good mechanical properties in terms of impact, toughness, strength and may be used in a wide variety of applications.
One problem with glass reinforced or carbon fiber reinforced composites is that the reinforcement fibers are generally abrasive. This abrasiveness can adversely affect equipment used to mold the composite parts. This in turn increases the cost for manufacturing reinforced composites parts due to increased mold turnover and downtime associated with mold turnover.
Another problem with glass reinforced or carbon fiber reinforced composites is that the fiber tends to break during injection molding and extrusion compression molding processing. Thus, recycled parts made of reinforced composites lose significant mechanical properties associated with fiber length within the composite material during processing. Impact resistance is, in most cases, the most significantly affected mechanical property. However, strength and modulus may suffer as well.
Further, composite parts cannot be recycled without further degrading fibers within the composite material. Therefore, composite parts not made to exact specifications are disposed of as waste.